DESCRIPTION (adapted from the application): This program will train physician scientists for productive careers pursuing the fundamental scientific investigation of infectious diseases. Even in the United States, infectious diseases remain the third most common cause of death, despite the wide availability of antibiotics, vaccines and high hygienic standards. Worldwide, infectious diseases are the leading cause of death. The identification of new pathogens, the reemergence of old pathogens and the steady acquisition of antibiotic resistance reflect the globalization of humanity and microbes, and new and old pathogens can be rapidly moved great distances and establish footholds in new niches. Strategies for control of infectious diseases will rely increasingly on merging strong epidemiologic and population-based approaches with fundamental bench research that takes advantage of rapid advances in genomics, pathogenesis and immunology. The UCSF training program in infectious diseases will provide training in two tracks clinical investigator and basic investigator that will provide a structured environment for exposure to the tools and scientific creativity that will be required for a successful career in the discipline. These tracks are based on recommendations formulated after regional and national meetings of infectious diseases division chiefs and program directors. Synergy between the two tracks is planned so as to generate new research opportunities with the potential to accelerate greatly knowledge and progress in the field. Training will focus on MD and MD/PhD applicants, but postdoctoral PhD trainees with the appropriate training and interests will be eligible to apply.